PREPARING Become a MATIZEN What is Math Planet ? A Crash Course on      Algebra A Crash Course on      Geometry   EXPLORING Advanced Math Topic Customized Lessons SAT & ACT Reviews   INTERACTING Math Games Discussion Forum Math Live! Chat   COLLECTING Math Search MATIZEN Qualifi-      -cation Test Acknowledgements The Creatures Behind      the Math Planet     ©1998 ThinkQuest team 16284 All rights reserved

# Geometry Glossary - R a|b|c|d|e|g|h|i|k|l|m|o|p|q|r|s|t|v|x|y|

Search the Word of Your Choice Here:

(Disabled by ThinkQuest

In a circle, a radius is a segment from the center to any point on the circle.

# radius of a regular polygon:

A radius of the regular polygon is a segment from the center to a vertex of the polygon.

# ray:

XY consists of 3FY and all points P such that Y is between X and P.

# rectangle:

A parallelogram with four right angles.

# reflection:

In a plane, a reflection about line I is a transformation which maps each point P into a point P such that (1) if P is on 1, then P' = P, and (2) if P is not on 1, then I is the perpendicular bisector of PP'.

# regular polygon:

A convex polygon that is both equilateral and equiangular.

# regular polyhedron:

A polyhedron in which all the faces are congruent regular polygons.

# remote interior angle:

An interior angle that is not adjacent to the given exterior angle.

# rhombus:

A parallelogram with four congruent sides.

# right angle:

An angle with a measure of 90.

# right cylinder:

A cylinder in which a segment connecting a pair of corresponding points of the bases is perpendicular to the bases.

# right prism:

A prism in which the lateral edges are perpendicular to the bases.

# right triangle:

A triangle with one right angle.

# rotation:

A rotation Rp,,,, of point A about point P through an angle of measure m is a transformation which maps A into its rota- tion image A' such that PA = PA' and m Z-APA' = m.

# rotational symmetry:

A figure has rotational symmetry if there is a rotation in which the figure and its image coincide under the rotation.

Note: The terms in this collection may not be entirely accurate.
They are for reference only.